I will state here what I know. Which is not too much, I am afraid. I am a postdoc in China since almost 2 years. I am not planning on staying longer as I did not identify with their work culture in the academia. Therefore I did not invest much of my time into learning about funding in China and applying for grants.
From my understanding there are several funding sources, the main ones being Province-level and National-level. They open calls for applications at different times of the year; e.g. September and March. Chances of success are highly dependent on your 'face' with your peers, the status of your college/institution, and nature of the grant call. Foreigners have an edge nowadays, particularly as there are grants specific for international projects. Currently in Biology the main topics being funded revolve around 'applied agriculture' and a few 'hot' fields such as STEM cells, CRISPR.
Currently (as of 2015-2017) there is a lot of funding available for research in China. Grants vary in amount of money they can provide, varying from what I've heard from mere 10k USD to much more. However one should be aware that grants come with specifications on what they should be spent on. For instance, there are grants which more flexible (usually modest) and more voluminous budgets for purchasing equipment, or others dedicated to "projects". I have heard of grants above 100k USD as you mention, for specific projects and head-start for fresh professors. The way it works, there are always workarounds in spending the money outside of the rules, but that will depend on knowing the ways and a lot of 'guanxi'. Beware of being caught redhanded as regulatory measures can be quite strict in modern China.
That said, it is my opinion that 100k USD per year sounds like excellent funding opportunity, but obviously the amount must be gauged in face of what it is, general context, and how it should be spent. If that includes salary, conference stipends, publication charges, and no significant structure or equipment is already available, this amount is likely not much. Keep in mind that because of careless handling and a lack of a maintenance culture, quite frequently equipment which appear listed as available at Chinese institutions actually may not be working properly... hence you may have to negotiate new ones.
I was attracted to my postdoc position by being shown pictures of heavy equipment such as a GC, centrifuges, PCR machines, microscopes, a lyophiliser, which in the end are not working but just sitting around.
My advice: visit first, take a long critical look around, and see through what is being promised and, most importantly implied between vague statements and contract lines. There is a lot of opportunity in China but one must be prepared for some intricate game.